The present invention relates to a device for measuring tensile stress acting on a seat belt.
U.S. Pat. No. 6,081,759 teaches a device for measuring tensile stress that comprises two components. A first component is connected with the seat belt and is supported via a spring on a second component connected firmly to the vehicle as an end fitting. The first component is mounted so as to be movable against the force of the spring relative to the second component fixed to the vehicle as a result of a tensile force acting on the seat belt. This movement is detected by a transducer that generates an electrical measuring signal proportional to the movement and thus to the tensile force acting on the belt webbing. The transducer takes the form of a GMR (Giant magneto-resistive) sensor.
There is provided in accordance with the present invention a device for measuring tensile stress acting on a vehicle seat belt, comprising: (a) a first component that may be connected with the seat belt; (b) a second component that may be fixed to a structural component of a vehicle; (c) a spring arranged between the two components and against whose force the two components may be moved relative to one another; and (d) a transducer having transducer elements that are attached to the first and second components and produces electrical signals as a function of the positions of the first and second components relative to one another, wherein the transducer produces a switching signal when the components are in a first positional zone; and in a second positional zone, in which the two components may be moved relative to one another against the force of the spring, the transducer produces measuring signals proportional to the movement of the two components relative to one another.